Objective: To investigate the clinical implications of cardiac troponin I (cTnI), myoglobin (Mb), creatine kinase (CK) and creatine kinase isoenzyme (CK-MB) in patients with acute myocardial infarction (AMI).
Methods: The serum concentrations of cTnI and Mb were determined in 50 patients with AMI 2 to 4 h after chest pain onset and compared with those measured in 50 age-matched healthy subjects.
Results: The serum levels of cTnI, CK-MB and CK in patients with AMI were significantly higher than those in the control group. Mb levels in AMI group were above the normal range. Mb, CK-MB, CK and cTnI reached the peak levels at 8+/-2.2, 18.1+/-3.2, 19.4+/-4.1 and 18.6+/-2.9 h after the onset, respectively, and their levels increased with the aggravation of AMI and were reduced to the normal levels with the amelioration of the disease. All the 4 indices were normal in the control group.
Conclusion: cTnI and Mb are reliable biochemical markers for early diagnosis of AMI and the changes in their serum levels have clinical significance in diagnoses and prognostic judgment of AMI.